Several years ago I had a horrific fall that took months to recover - physically. Severe concussion that had me unconscious of over 5 min., cracked pelvis, broken ribs, scrapes and bruises. After a lifetime of riding I was petrified to get back on a horse. At the time of the accident I had just bought a horse that I hadn't ridden yet and, although I was perfectly fine handling her, I was almost in tears when I forced myself to finally mount up a few months after the fall.
It took over a year and a few different horses to get enough courage to ride the trails again. Even now, several years after the accident, at times, I still get butterflies when I mount a new horse.
It helps to ride a confidence builder and to ride with friends. You take courage from other riders and a good horse will help you make the comeback. The horse I am riding now, Hollywood, is a high performance gelding and it took a lot of horses inbetween then and now to be able to ride him. If I had him right after the fall, I never would have gotten back it the saddle again - he would have been the wrong horse then but he's the perfect horse now.